Copier for greater than standard length documents

Abstract

An electrostatic reproduction machine having an improved control circuit to control turn on of a discharge lamp positioned to discharge a moving photoconductive belt member prior to development thereof. The control circuit enables a first mode of operation for copying standard length documents of 81/2 inches in length and a second mode of operation for copying documents greater in length than 81/2 inches without erasing image areas by the discharge lamp. For the second mode of operation an RC adjustable circuit enables a suitable delay before lamp turn on. A machine operator can easily select the desired mode of operation.

What is claimed is: 
     
       1. In an electrostatic reproduction machine including a photoconductive member moveable past processing stations including means for charging said member, means for exposing said member to document information to produce latent electrostatic images thereof on said member, means for developing the electrostatic images on said member and a discharge lamp positioned upstream from said developing means at a predetermined position operative to discharge said photoconductive member for a predetermined period prior to its advancing to the development station, and the improvement wherein circuit means for providing control signals in a first mode of operation to activate said discharge lamp at a preset interval corresponding to a standard document dimension, said circuit means includes means for providing control signals in a second mode of operation to activate said discharge lamp at preset intervals which are delayed from a reference associated with the intervals of said standard document dimension to enable imaging from document information having a dimension greater than said standard document dimension, and   switching means for selecting either said first or second mode of operation at the option of a machine operator.   
     
     
       2. A machine according to claim 1 wherein said circuit means includes an adjustable RC circuit means to control selectively turn on of said discharge lamp. 
     
     
       3. A machine according to claim 2 wherein said RC circuit means includes capacitance means coupled to ground whereby if a discontinuity occurs in wiring coupled to said switching means, the machine reverts automatically to said first mode of operation.